The new Zero Trim piling technique will reduce health and safety risks and significantly reduce carbon emissions, cost, noise and programme durations.
The Zero Trim piling solution has been developed jointly by Cementation Skanska and the Skanska Costain STRABAG joint venture that is delivering the London Tunnels section of HS2.
The technique uses a vacuum excavator that sucks out excess concrete from a pile while it’s still wet – traditionally the concrete is overpoured and then site teams have to break out the excess concrete. This can cause health problems, including hand-arm vibration syndrome, hearing loss and silicosis. This new approach removes the need to do this, creating a safer method for people in the industry.
There are further positive benefits, including noise reduction which is important for projects like HS2 where construction is taking place within communities and near operational businesses. There are also considerable cost savings and environmental benefits as the new technique uses less concrete, reducing carbon. On the Skanska Costain STRABAG JV work for HS2, the extracted concrete is being retained on site and being reused in construction elsewhere. This reduces carbon in construction, including through reduced lorry movements to and from site.
The zero trim technique was developed jointly by Lee Piper from the Skanska Costain STRABAG joint venture, Deon Louw from Cementation Skanska and specialist sub-contractor Hercules Site Services.
Deon Louw, Project Director, Cementation Skanska, said: “This piling innovation has been developed as a result of a fantastically collaborative approach. This included trials with Hercules Site Services to perfect the vacuuming technique, together with extensive onsite testing to validate the integrity of the piles constructed using this new approach.
“We’ll be installing around 2000 piles over the next three years in the Euston area. This zero trim innovation will bring amazing benefits in terms of reduced carbon, noise reduction and safer ways of working for our site teams. The potential health impacts associated with concrete breakdown are well known, so to be able to mitigate these risks from the outset is great for our people.
“Longer-term, we’ll be looking to see how we can use this innovation on future projects. It really does have the potential to be a game-changer for our industry.”
Lee Piper, Site Superintendent for Skanska Costain STRABAG joint venture added: “I have worked in the construction sector for over 20 years, and the same piling techniques have been used throughout that time. Working with colleagues I saw an opportunity to try a new approach and was supported to do so by HS2 as the project client.
“This technique could be transformational for the construction sector, reducing the health risk that results from breaking piles. The additional benefits of noise reduction, time and carbon savings mean the technique should be attractive for the whole sector to use going forward.”
Malcolm Codling, Client Director for HS2, said: “HS2 is an ambitious project and in order to deliver it, we need to innovate. We are proud to be supporting our contractors to deliver these world class transformational innovations, and to support them to be adopted across the project to help reap the benefits.
“At the site near Euston where this technique has already been put into practice, we estimate it will save 60,000 manhours, have a significant positive impact on the health and wellbeing of our staff, reduce noise for nearby residents as well as removing carbon from the construction process. Delivering this across the route could have a major impact on the HS2 project.”
Discussions are taking place with other HS2 contractors to see how the technique can be used further across the route.